Inkjet-printed thin-film transistors using surfactant-based transition-metal dichalcogenide nanocomposites suspended in polymeric semiconductors

• Published in: Flexible and printed electronics Vol. 9; no. 1
• Main Authors: Choi, Hyunwoo, Park, Wontae, Lee, Yebin, Tam, Kam C, Wong, William S
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.03.2024
• Subjects: inkjet-printed thin film transistors; polymeric semiconductor; transition-metal dichalcogenides
• ISSN: 2058-8585; 2058-8585
• DOI: 10.1088/2058-8585/ad1e2b

Abstract Ink formulations containing a suspension of single-crystalline molybdenum disulfide (MoS 2 ) nanosheets suspended in the polymeric semiconductor poly(3-hexylthiophene-2,5-diyl) (P3HT) were inkjet printed for the fabrication of thin-film transistors. The MoS 2 nanosheets were treated with the surfactant trichloro(dodecyl)silane (DDTS) to functionalize the MoS 2 surface and created a more stable suspension, reducing the agglomeration of MoS 2 suspended in the P3HT solution. This ink formulation was inkjet printed onto the surface of thermal oxide coated, p + -Si wafers to form common-gate thin-film transistor (TFT) device structures. The printed semiconductor formed the active region of a hybrid MoS 2 suspension in P3HT of the TFTs. The field-effect mobility for the hybrid-ink TFTs was found to be three times (3×) higher compared to reference devices using pristine P3HT without the suspension. The functionalized MoS 2 suspension was also found to form thinner nanosheet suspensions within the P3HT matrix that resulted in approximately 60% higher field-effect mobility compared to hybrid inks without the surfactant. The enhancement of the electrical properties of the TFTs was determined to be due to a structural change in the thin-film semiconductor. The observed current-voltage ( I - V ) changes were correlated to measurable structural alterations in the semiconductor thin film characterized by X-ray diffraction, atomic force microscopy, and UV-visible absorption spectroscopy.